
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author fe500728
 */
public class Deconnexion extends HttpServlet {

    String login = "";
    String Massage = "";

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        try {
            /* TODO output your page here
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet BlackCat</title>");
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>Servlet BlackCat at " + request.getContextPath () + "</h1>");
            out.println("</body>");
            out.println("</html>");
             */
            response.setContentType("text/xml");
            OutputStream os = response.getOutputStream();
            OutputStreamWriter osw = new OutputStreamWriter(os, "UTF-8");
            PrintWriter pw = new PrintWriter(osw);




        } finally {
            out.close();
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //processRequest(request, response);
        String fPathMessage = request.getRealPath("index.jsp").replace("index.jsp", "message.xml");
        String fPathOnline = request.getRealPath("index.jsp").replace("index.jsp", "online.xml");
        PrintWriter out = response.getWriter();
        login = request.getParameter("login");
        
        try {
            removeUser(login,fPathMessage,fPathOnline);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            out.close();
        }
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

    public void removeUser(String login, String fPathMessage, String fPathOnline) {
        try {

            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document doc = db.parse(fPathOnline);
            doc.getDocumentElement().normalize();
            
            NodeList nodeLst = doc.getElementsByTagName("users").item(0).getChildNodes();

            for (int s = 0; s < nodeLst.getLength(); s++) {

                Node fstNode = nodeLst.item(s);

                if (fstNode.getNodeType() == Node.ELEMENT_NODE) {


                    if (fstNode.getTextContent().equals(login)) {
                        doc.getElementsByTagName("users").item(0).removeChild(fstNode);
                    }



                }
            }

            Source source = new DOMSource(doc);

            File file = new File(fPathOnline.trim());
            file.createNewFile();

            doc.setDocumentURI(doc.getDocumentURI().trim());
            file.setWritable(true);
            Result result = new StreamResult(file.toURI().getPath());


            Transformer xformer = TransformerFactory.newInstance().newTransformer();
            xformer.transform(source, result);


            dbf = DocumentBuilderFactory.newInstance();
            db = dbf.newDocumentBuilder();
            doc = db.parse(fPathMessage);
            doc.getDocumentElement().normalize();
           
            
            if(doc.getElementsByTagName("users").item(0)==null){
                dbf = DocumentBuilderFactory.newInstance();
                db = dbf.newDocumentBuilder();
                doc = db.parse(fPathMessage);
                doc.getDocumentElement().normalize();

                nodeLst = doc.getElementsByTagName("messages").item(0).getChildNodes();
                boolean skipFirst=true;
                for (int s = 0; s < nodeLst.getLength(); s++) {

                    Node fstNode = nodeLst.item(s);

                    if (fstNode.getNodeType() == Node.ELEMENT_NODE) {


                        if (skipFirst==false) {
                            doc.getElementsByTagName("messages").item(0).removeChild(fstNode);
                        }
                        else{
                            skipFirst=false;
                        }



                    }
                }

                source = new DOMSource(doc);

                file = new File(fPathMessage.trim());
                file.createNewFile();

                doc.setDocumentURI(doc.getDocumentURI().trim());
                file.setWritable(true);
                result = new StreamResult(file.toURI().getPath());


                xformer = TransformerFactory.newInstance().newTransformer();
                xformer.transform(source, result);
            }
            


        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}